Given highway code part 163, how do you overtake on the wrong side of the road? The only valid answer, is to be on the same side of the road as the traffic you are overtaking. Was the cyclist behaviour careless and being 6 wide in breach of the highway code? Yes, was it dangerous? Not if you use the driving definitions of careless and dangerous which seem to include careless as killing a cyclist and just continuing on the road ignoring what you have just done with the cyclist on your bonnet for a few hundred yards.
What is the definition of the "wrong side of a roundabout" ? Were they heading round in the wrong direction? If so you have a valid and very serious point, if not then what on earth are you trying to describe? Again the highway code states that drivers should be aware of cyclists or horse riders sticking to the outside lane of a roundabout regardless of which exit they intend to take.
Congratulations, you have shown yourself to be a typical incompentant selfish driver.